System and method for liquid distribution

ABSTRACT

A liquid flow distributor for positioning above one or more packing sections in a packed exchange tower includes a plurality of troughs. At least one trough in the plurality of troughs has along a side thereto a deflecting member The deflecting member is angulated to generally follow a shape of the at least one trough. A diffuser side of the deflecting member is positioned to deposit the liquid into a discharge region. A plurality of break bars are disposed on the diffuser side of the deflecting member. A deflector side of the deflecting member is positioned for deflecting ascending vapor away from the discharge region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of, and incorporates byreference the entire disclosure of U.S. patent application Ser. No.13/564,881, filed Aug. 2, 2012, now U.S. Pat. No. 8,888,077. U.S. patentapplication Ser. No. 13/564,881 is a continuation of U.S. patentapplication Ser. No. 12/418,189, filed Apr. 3, 2009, now U.S. Pat. No.8,517,352. U.S. patent application Ser. No. 12/418,189 claims priorityto U.S. Provisional Patent Application 61/201,121, filed Dec. 5, 2008and U.S. Provisional Patent Application No. 61/042,519, filed Apr. 4,2008. U.S. patent application Ser. No. 12/418,189, U.S. ProvisionalPatent Application 61/201,121, and U.S. Provisional Patent ApplicationNo. 61/042,519 are incorporated herein by reference. This applicationclaims priority to, and incorporates by reference the entire disclosureof U.S. Provisional Patent Application No. 61/784,124, filed Mar. 14,2013.

BACKGROUND

1. Technical Field

The present invention pertains to liquid distributors andliquid-distribution methods for vapor-liquid contact towers, and, moreparticularly, but not by way of limitation, to distributor troughshaving one or more of deflector baffles, diffuser plates, break bars, ortubes in configurations allowing liquid to be spread into a continuousfilm dispersed onto underlying packing in a chemical process tower.

2. History of Related Art

It is well known in the prior art to utilize various types of exchangecolumns in which a gas and a liquid come into contact with one another,preferably in a counter-current flow for purposes of mass or heattransfer, close fractionation and/or separation of feed stockconstituents, and other unit operations. Efficient operation requiresmass transfer, heat transfer, fluid vaporization and/or condensation,whereby one of the fluids can be cooled with a minimum pressure dropthrough and in a particular zone or zones of minimum dimensions definingthe area and volume thereof. These are pre-requisites of efficientoperation and are necessary for close fractionation. For this reason,counter-current flow of vapor and liquid within such exchange columnshave become established methods of such vapor-liquid contact in theprior art. The actual vapor-liquid interface requires the utilization ofa packing bed within the column. Liquid is then distributed atop thepacking bed in the most feasible manner while vapor is distributedbeneath the packing bed in the lower region of the tower. In thismanner, liquid trickling downwardly through the packing bed is exposedto the vapor ascending therethrough for vapor-liquid contact andinteraction.

It is well established that the configuration of the packing beddetermines the pressure drop, capacity and efficiency of thevapor-liquid interface and the concomitant mass and energy transferoccurring in a process tower. The means for effective and evendistribution of the vapor and the liquid on opposite ends of the packingbed as well as maintenance of that distribution therethrough arecritical to efficient operation. Only with efficient initial vapor andliquid distribution and the maintenance of said distribution throughoutthe packing bed will homogenous mixing zones be created therethrough formaximizing the efficiency therein. Efficiency is readily convertible tocost of operation and production quality. For this reason, a myriad ofprior art packing designs have been prevalent in conventional exchangecolumns. The efficiency of the packing is, however, limited to a largeextent by the efficiency of the vapor and liquid distributionthereacross. For example, failure of either vapor or liquid to evenlydistribute over cross sections of the packing effectively eliminates theutility of the part of the packing where there is poor or nodistribution which in turn is directly proportional to the efficiencyand cost-effectiveness of the operation. The packing bed depths arecritical in establishing production criteria and operational costs andfailure to evenly distribute vapor-liquid and/or maintain homogeneitywithin the packing bed can lead to serious consequences, particularly inthe petroleum refining industry.

Aside from the packing beds themselves, the liquid distributor is themost important unit of a tower internal. Failure in performance of apacked tower sometimes stems from liquid distribution problems such asclogging or uneven distribution and thus the selection of a correctliquid distributor is critical for uninterrupted plant operation.Operational considerations thus include the functional aspects of thedistributor, such as how level the distributor troughs are maintained,how well the floor is equalized therethrough, and the means throughwhich the liquid is distributed from the troughs to the packing bedstherebeneath. Also considered is the effect which the ascending vaporhas on the liquid being distributed. When vapor flow areas arerestricted flow velocity can increase to the point of interrupting thedescending flow pattern. The liquid is, in essence, “blown” around, andthis condition can lead to uneven distribution and inefficiency in theprocess column.

Conventional liquid distributors generally include the multi-orificespray head variety adapted for dispersing liquid in the form of a sprayatop a packing bed. In the utilization of dump packing wherein aplurality of random oriented packing elements are disposed, within theexchange column, such a liquid distribution technique is sometimeseffective. This is true particularly when high efficiency parameters arenot of critical significance.

The cost of high efficiency packing of the type set forth in theaforesaid patent commands attention to proper vapor-liquid distribution.Even small regions of non-homogenous interaction between the vapor andliquid is an expensive and wasteful loss not consistent with theutilization of high efficiency packing, where space and homogeneity invapor-liquid interface is both expected and necessary for properoperation. High efficiency packing typically requires counter-currentvapor-liquid flow through the channels defined by opposed corrugationsof sheets disposed therein. If the initial liquid or gas distributionfails to enter a particular corrugation pattern, then precious surfacearea is lost in the packing until the liquid and vapor are urged tomigrate into and interact through the unfilled regions of the packing.Only by utilizing proper vapor and liquid distribution means mayeffective and efficient utilization of high efficiency packing as wellas conventional dumped packing be assured.

The development of systems for adequate liquid distribution in processtowers has been limited as set forth above. In the main, it is known todischarge and distribute liquids with spray orifices, pipes, perforatedplates, apertured troughs and nozzles. Gas is concomitantly dischargedin an ascending turbulent configuration to provide adequate vapordistribution. Although many prior art systems are generally effective indistributing some vapor and some liquid to most portions of the packingbed, uniform distribution thereacross is usually not obtained withoutmore sophisticated distribution apparatus. For example, unless gas isinjected into a myriad of contiguous areas beneath the packing bed withequal pressure in each area, the mass flow of vapor upwardly through thepacking bed cannot be uniform. Random vapor discharge simply distributesunequal amounts of vapor across the lower regions of the packing bed butdoes not in any way assure equality in the distribution. Likewise thesimple spray of liquid atop the packing bed, though intended to beeffective in wetting all surface areas, often results in highconcentrations of liquid flow in certain packing bed areas and less flowin others. This, of course, depends on the spray device. Orificedistributors are generally more susceptible to plugging than other typesof distributors, and plugging is generally non-uniform to unevenirrigation within the tower. Surface irregularities in a distributor panoccurring during manufacture likewise increase flow resistance of someperforations or induce liquid flow along the bottom of the pan which isa distinct disadvantage. Any flow irregularity which focuses the flow inone area while reducing flow in other areas is deleterious.

It has been discovered that with pipe distributors consisting of headersequipped with tributary pipes or laterals that have holes or nozzles tospray liquid, the liquid is often distributed too finely. Tiny drops ofthe liquid then get carried out of the tower by counter-current gasflow. This prevents the liquid from even coming in contact with thepacking bed. Since liquid contact is the purpose of the packingtherebeneath, such a result totally frustrates the intent of the liquiddistributor. As much as 5% of the liquid flowing through a nozzle can beconverted to mist at a pressure drop of 20 psi. It has also been notedthat nozzle equipped pipe distributors can produce overlapping spraypatterns which result in increased flow in certain areas with reducedflow in other areas. Moreover, spray headers also release liquid atspeeds that can cause it to pass vertically through the packing beforeit has a chance to spread out horizontally depending on the particularpacking type.

These issues are important as well as the critical issue of the numberof liquid distribution points necessary for various tower diameters,packing heights, materials and systems. It is critical that the packingheight not be too great wherein the weight of the packing will cause itto crush itself. However, liquid redistributors between packing sectionsare expensive and take up heights that could otherwise be used for masstransfer. One consideration is the type of packing being used.Structured packing is best in deep bed depths; however, liquiddistribution must be uniform.

In light of the above, various liquid distributor designs have beendeveloped for addressing such critical issues. The following U.S.patents specifically set forth for the purposes of describing earlierdesigns addressing liquid distribution. These patents include U.S. Pat.No. 6,722,639 to Ender; U.S. Pat. No. 6,293,526 to Fischer; U.S. Pat.No. 5,906,773 to Hausch; U.S. Pat. No. 4,909,967 to Binkley; U.S. Pat.No. 4,855,089 to Michels; U.S. Pat. No. 4,816,191 to Berven; U.S. Pat.No. 4,729,857 to Lee; U.S. Pat. No. 5,051,214 to Chen; U.S. Pat. No.5,192,465 to Petrich; and U.S. Pat. No. 6,502,806 to Richardson. Thesepatents illustrate various embodiments of liquid distribution forchemical process towers.

Unfortunately, the manifestation of uneven liquid distribution generallyoccurs in the vicinity of the most even, or uniform, vapor distribution.The opposite is also true. This is because vapor has had a chance tomore evenly distribute through the packing bed prior to engaging theliquid distribution flow. It would be an advantage, therefore, toprovide means for even liquid and vapor distribution prior to entry ofsaid vapor and liquid into the packing bed and in a manner providingboth a uniform spread of said liquid and vapor and uniform volumetricdistribution thereof.

The present invention provides such an improved system of vapor-liquiddistribution through a trough distributor wherein each troughdistributor is constructed with a particular configuration facilitatingmaximum efficiency. In some embodiments, deflector plates, bafflesand/or tubes may be utilized in accordance with the principles of thepresent invention as well as various configurations of the troughitself.

SUMMARY OF THE INVENTION

The present invention pertains to liquid distributors andliquid-distribution methods for vapor-liquid contact towers, and, moreparticularly, but not by way of limitation, to distributor troughshaving one or more of deflector baffles, diffuser plates, break bars, ortubes in configurations allowing liquid to be spread into a continuousfilm dispersed onto underlying packing in a chemical process tower.

In one aspect, the present invention relates to a packed exchange towerthat includes one or more packing sections disposed in the tower forfacilitating the interaction of vapor and liquid passing in acounter-flow therethrough. One or more liquid flow distributors arepositioned above the one or more packing sections for even distributionof the liquid downwardly therethrough. The one or more liquid flowdistributors include a plurality of troughs for dispersing the liquidthereacross. At least one trough of the plurality of troughs isconfigured for dispersing the liquid in a deflecting-memberconfiguration. The at least one trough has at least one deflectingmember disposed along a first side. The at least one deflecting memberis used for maximizing efficiency of vapor-liquid interaction. Theliquid-flow distributor includes a diffuser plate extending from the atleast one deflecting member. The at least one deflecting memberdischarges the liquid against the diffuser plate for uniformlydistributing the liquid across the plurality of packing sections. The atleast one deflecting member includes a deflector side facing outwardlyof the at least one trough and a diffuser side facing the at least onetrough. The at least one deflecting member is angulated to generallyfollow a shape of the at least one trough. At least one break bardisposed on the diffuser side of the at least one deflecting member. Theat least one break bar induces the liquid to flow along the diffuserside of the at least one deflecting member in a continuous sheet. Thedeflector side of the at least one deflecting member is positioned fordeflecting ascending vapor away from the downward flow of the liquid onthe diffuser side.

In another aspect, the present invention relates to a packed exchangetower that includes one or more packing sections disposed in the towerfor facilitating the interaction of vapor and liquid. One or more liquidflow distributors are positioned above the one or more packing sections.The one or more liquid flow distributors include a plurality of troughsfor dispersing the liquid. At least one trough of the plurality oftroughs having a shape that includes a curvilinear formation on a firstside of a bottom region thereof and an angulated formation on a secondside of the bottom region thereof. A deflecting member is disposed alonga selected side of the at least one trough for use in conjunction withthe at least one trough for maximizing efficiency of vapor-liquidinteraction. The deflecting member includes a deflector side facingoutwardly of the at least one trough and a diffuser side facing the atleast one trough. The deflecting member is angulated to generally followthe shape of the at least one trough. The deflector side of thedeflecting member is positioned for deflecting ascending vapor away fromdownward flow of the liquid on the diffuser side. At least one break baris disposed on the diffuser side of the deflecting member. The at leastone break bar induces the liquid to flow along the diffuser side of thedeflecting member in a continuous sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the presentinvention may be obtained by reference to the following DetailedDescription when taken in conjunction with the accompanying Drawingswherein:

For a more complete understanding of the present invention and forfurther objects and advantages thereof, reference may now be had to thefollowing description taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is a perspective view of a packed column with various sectionscut away for illustrating a variety of tower internals;

FIG. 2 is an enlarged side-elevational, cross-sectional view of theliquid flow distributor of FIG. 1;

FIG. 3 is a diagrammatical, side-elevational, cross-sectional view ofone embodiment of a liquid distributor;

FIG. 4 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 5 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 6 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 7 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 8 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 9 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 10 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 11 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 12 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 13 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 14 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 15 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 16 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIG. 17 is a diagrammatical, side-elevational, cross-sectional view ofanother embodiment of a liquid distributor;

FIGS. 18A-18F comprise a series of drawings representing variousembodiments of drip tubes;

FIGS. 19A-B are diagrammatical side-elevational, cross-sectional viewsof a liquid distributor utilizing a plurality of break bars;

FIGS. 19C-F are frontal planar views of a baffle plate utilizing aplurality of break bars;

FIG. 19G is a diagrammatical side-elevational, cross-sectional view of aliquid distributor utilizing a plurality of ripples;

FIGS. 20A-20C are diagrammatical side-elevational, cross-sectional viewsof a liquid distributor according to exemplary embodiments; and

FIGS. 21A-21B are diagrammatical side-elevational, cross-sectional viewsof a liquid distributor according to exemplary embodiments.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

Although various embodiments of the method and apparatus of the presentinvention have been illustrated in the accompanying Drawings anddescribed in the foregoing Detailed Description, it will be understoodthat the invention is not limited to the embodiments disclosed, but iscapable of numerous rearrangements, modifications and substitutionswithout departing from the spirit of the invention as set forth herein.

Referring first to FIG. 1, there is shown a perspective view of a packedexchange tower or column with various sections cut away for illustratinga variety of internals. The exchange column 10 of FIG. 1 comprises acylindrical tower 12 having a plurality of packing bed layers 14disposed therein. A plurality of manways 16 are likewise constructed forfacilitating access to the internal region of the tower 12 forreplacement of the packing beds 14. Also provided are side stream drawoff line 20, liquid side feed line 18, and side stream vapor feed lineor reboiler return line 32. A reflux return line 34 is provided atop thetower 10.

In operation, liquid 13 is fed into the tower 10 through reflux returnline 34 and side stream feed input feed line 18. The liquid 13 flowsdownwardly through the tower and ultimately leaves the tower either atside stream draw off 20, or at bottom stream draw off line 30. In itsdownward flow, the liquid 13 is depleted of some material whichevaporates from it as it passes through the packing beds, and isenriched or added to by material which condenses into it out of thevapor stream.

Still referring to FIG. 1 the exchange column 10 further includes avapor outlet, overhead line 26 disposed atop the tower 12 and a lowerskirt 28 disposed in the lower region of the tower around bottom streamtakeoff line 30 coupled to a reboiler (not shown). Reboiler returnconduit 32 is shown disposed above the skirt 28 for recycling vaportherein upwardly through the packing layers 14. Reflux from condensersis provided in the upper toward region 23 through entry conduit 34wherein reflux is distributed throughout a liquid distributor 36 acrossupper packing bed 38. It may be seen that the upper packing bed 38 is ofthe structured packing variety. The regions of the exchange column 10beneath the upper packing bed 38 are shown for purpose of illustrationand include a liquid collector 40 disposed beneath a support grid 41 insupport of the upper structured packing 38. A liquid redistributor 42 islikewise disposed therebeneath and an intermediate support plate 4 isprovided in an alternative configuration of the type adapted forsupporting random packing 14A of a ring or saddle variety asrepresentatively shown. A lower grid 46 is illustrated disposed beneatha liquid distributor 48 comprising a plurality of troughs 49 adapted fordispersing the liquid 13 thereacross in counter-current flow to theascending vapor therebeneath. It may be seen from this figure that thecountercurrent configuration between the ascending vapor 15 and thedescending liquid is the subject of a plurality of critical designconsiderations including liquid/vapor ratios, liquid cooling, foamingand the presence of solids or slurries therein. Corrosion is likewise aconsideration of the various elements in the packed towers and theselection of the material in the fabrication of the tower internals isin many instances the results thereof.

Referring now to FIG. 2 there is shown an enlarged end-elevationalcross-sectional view of the prior art trough 49 of FIG. 1 having a lowerbody section 50. This particular embodiment of prior art liquiddistribution is most fully set forth in U.S. Pat. No. 4,909,967. Thetrough section 50 is comprised of outer walls 52 and 54 upstanding froma bottom surface 60. A series of upper apertures 56 and lower apertures58 are formed in the side walls 52 and 54 for purposes of allowingliquid flow outwardly of the trough 49. Outwardly of the apertures 56and 58 is a removable distributor tube assembly adapted for receivingthe flow of liquid therefrom and channeling said liquid downwardly intoa packing bed therebeneath (not shown). Each tube assembly 62 comprisesa modified U-shaped channel 64 that is secured to the side wall of thetrough 49 by arc welding or the like. The channel 64 is constructed witha substantially planar base wall 66 and two upstanding side wall lips 68and 70. Only one of the side walls 68 and 70 is shown on opposite sidesof trough 49 in FIG. 2 because of the cross-sectional angle, and thenonly in phantom. What is shown is an aperture 57 formed in base wall 66in line with aperture 56 and an aperture 59 formed in base wall 66 inline with aperture 58. A generally V-shaped channel 72 of mating size isreceived within the U-shaped channel 64 in slidable engagement therewithproviding the necessary assemblage for serving as a flow distributordrip tube that is both efficient and removable.

Referring now to FIG. 3 there is shown a diagrammatical,side-elevational, cross-sectional view of a liquid flow distributortrough 149 having a lower body section 150. The trough section 150 iscomprised of side walls and a bottom along with a series of aperturesformed in the side walls for allowing liquid flow outwardly therefrom inthe manner generally described in FIG. 2 for prior art trough 49. Itshould be recognized that liquid distributor troughs will, bydefinition, have side walls and a bottom as well as apertures and/orother means of liquid discharge and the description of the variousembodiments of the present invention for FIGS. 3-17 is presented hereinin illustration of the various aspects of the present invention relativeto the utilization of a trough design in a chemical process tower of thegeneral type shown in FIGS. 1 and 2. In some instances, upper and lowerdischarge apertures will be set forth, shown, and described. Theapertures allow liquid flow outwardly from the trough. In someembodiments, tubes may be secured to the outside of the trough. Itshould be noted that the prior art trough of FIGS. 1 and 2 areillustrated with tubes utilized for flow distribution in the form of adistributor tube. In the present invention, distributor tubes may or maynot be used.

Still referring to FIG. 3, the liquid is discharged from the trough 150through upper and lower apertures 156 and 158 formed in the side wall ofthe trough. Disposed outwardly of the apertures 156 and 158 is deflectorbaffle 160 constructed in a generally reverse L-shaped configuration anddisposed such that the lower region thereof is generally orperpendicular to and spaced from a diffuser plate 170. The diffuserplate 170 may be welded to and/or an extension of the trough itself. Theexact method of manufacture may vary in accordance with the principlesof the present invention.

Still referring to FIG. 3, as liquid is discharged from upper and lowerapertures 156 and 158, the liquid flows down an inner side of thedeflector baffle 160, also referred to herein as a diffuser side, and isdeposited beneath the trough 150 and above the underlying packing, alsoreferred to herein as a discharge region. Specifically, in the dischargeregion, the liquid is discharged against surface 170A of diffuser plate170 which allows the liquid to spread out and be uniformly distributedacross the underlying packing therebeneath. As shown in FIG. 3,ascending vapor 302 ingressing toward descending liquid flow in thedischarge region engages an outer side of the deflector baffle 160, alsoreferred to herein as a deflector side. Thus, the ascending vapor 302may be deflected away from the discharge region. Other means to lowerthe operating pressure drop and reduce entrainment are also afforded bythe designs of multiple ones of the other configurations in FIGS. 5-17.

Referring now to FIG. 4, there is shown an alternative configuration ofthe distributor trough of FIG. 3. When liquid discharge is present onboth sides of a distributor trough, as depicted in FIGS. 4-7, more thanone deflector baffle may be necessary. Accordingly, in FIG. 4, a seconddeflector baffle 160A is shown along with a second set of apertures 156Aand 158A. Optional rows of apertures may also be included as required,which are, for example, shown in FIG. 4 as 159 and 159A. As describedabove, ascending vapor 302 engages a deflector side of the seconddeflector baffle 160A. In this manner, the ascending vapor 302 isdeflected so as to minimize interference with the discharge of liquidevenly across the diffuser plate. FIGS. 5-7 depict additionalembodiments including two deflector baffles.

Referring now to FIG. 5, there is shown yet another embodiment of thepresent invention wherein a distributor trough 249 includes sidewalls250 and an angulated bottom region 252 which forms a generally V-shapedconfiguration. This shape of trough reduces pressure drop, and likewisein FIGS. 6-7 and FIGS. 10-17. Likewise, a pair of deflector baffles 260is provided on opposite sides of the trough 250 and positioned todischarge liquid against at least one diffuser plate 270 depending fromthe angulated bottom region 252 of the trough 250.

Referring now to FIG. 6, there is shown a trough 250A also having a pairof oppositely disposed deflector baffles 260, but further having avariation in that diffuser plate 270 depends from a substantially planarbottom region of the trough 250A. Similarly, in FIG. 7, a trough 250B isshown with a bottom region 252B that is of arcuate and/or otherwisecurved configuration as compared to the angular configuration of FIG. 6.

Referring now to FIG. 8, there is shown a trough 350 similar to thatshown in FIG. 3, except that the diffuser plate 370 is not connecteddirectly to the bottom of the trough 350, but, instead, to the deflectorbaffle 360. It may be seen that the liquid descending from the aperturesand side wall of the trough 350 would spread along surface 370A ofdiffuser plate 370.

Referring now to FIG. 9, there is shown the trough 350 of FIG. 8 with avariation in the deflector baffle. A deflector baffle 360A isconstructed to have a lower region 361 extending substantially acrossthe bottom of the trough 350 such that the diffuser plate 370B ispositioned, not in the center, but generally beneath a side of thetrough 350. In various embodiments, a non-fouling orifice or aperturemay be formed in the bottom of the trough 350 for discharge of liquidagainst the lower region of the deflector baffle 360A. Examples ofnon-fouling orifices or apertures in a bottom region of a trough arediscussed below relative to FIGS. 11 and 16-17.

Referring now to FIG. 10, there is shown a distributor trough 450similar in design to the distributor trough of FIG. 5 wherein anangulated bottom region is formed therewith. In this particularembodiment, a deflector baffle 460 is angulated such that it isconnected directly to the diffuser plate 470 disposed therebeneath. Inthis manner, ascending vapor 302 is diverted upwardly and around thetrough 450 as shown.

Referring now to FIG. 11, there is shown an alternative embodiment ofthe trough of FIG. 10. In this particular embodiment, trough 450Aincludes a non-fouling orifice 458 formed in one of the angulatedsidewalls for discharge of liquid against the deflector baffle. Thedeflector baffle includes a continuous diffuser plate 470 formedtherebeneath. In this particular embodiment, the deflector baffle 460Adoes not extend as far upwardly along the side of the trough for 450Abut this is only one embodiment of the present invention.

Referring now to FIGS. 12-17, in combination, there is shown a series ofalternative embodiments of distributor trough shapes as compared tothose set forth in FIGS. 3-11. In these particular embodiments, thedistributor trough is formed with angulated side and/or bottom wallsthat may be of angled and curvilinear formation to provide improvementrelative to both a discharge of liquid as well as the deflection of theascending vapor 302. In this manner, entrainment is reduced andefficiency is increased.

Referring now specifically to FIG. 12, there is shown a distributortrough 550 with an angulated bottom region 552 to further facilitate thedeflection of ascending vapor 302 as shown. In this particularconfiguration, an optional tube 553 is shown to further facilitate thecontrol of the liquid discharge from the trough 550. Likewise thediffuser plate 570 of this particular configuration is shown to beconnected to, and extending from, the bottom region 552 of trough 550.

Referring now to FIG. 13, a distributor trough 650 is shown comprisingan angulated bottom region 652 oppositely disposed to that of trough 550shown in FIG. 12. In this particular embodiment, it is shown that atubular baffle may be utilized, although, in this particularillustration, a baffle 660 is shown adapted for discharging liquid ontoa diffuser plate 670 connected directly to the bottom region of trough650. A variation of this design is shown in FIG. 14, where the deflectorbaffle 660A is angulated to receive the discharge from the trough 650Afrom two apertures formed therein. The liquid is then discharged beneaththe trough into the discharge region. Specifically, the liquid isdischarged upon a diffuser plate 670A depending directly from the lowerregion of the trough 650A.

Referring now to FIG. 15, a distributor trough 750 having an angulatedconstruction similar to that shown in FIG. 12 is illustrated with acontiguous deflector baffle and diffuser plate assembly 770 adapted forreceiving the discharge of liquid from an aperture 758. As representedon the drawings hereof, the contiguous deflector baffle and diffuserplate 770 may likewise include and/or be replaced by a tube assemblyused in conjunction therewith. The effectiveness of the deflection ofascending vapor 302 due to angulation of various members are shownherein. This similar labeling is represented also in FIG. 16 wherein thedistributor trough 750A, having a lower discharge aperture 758A formedin a bottom region of the trough 750A, discharges onto at least onecontiguous deflector baffle and diffuser plate 770A in such aconfiguration facilitates liquid flow through orifices and preventsfouling. The liquid discharge aperture 758B shown FIG. 17 for trough750B has a similar design except for the location of the liquiddischarge aperture. Likewise, an optional modification of the contiguousdeflector baffle and diffuser plate 770B is shown where the uppermostportion is closed and in contact with a side wall of the trough 750B.Closure prevents ascending vapor 302 from passing therethrough in amanner that could interfere with uniform liquid flow.

In operation, the various embodiments of the present invention shown inFIGS. 3-17 facilitate the discharge of liquid in a chemical vapor-liquidprocess column having ascending vapor therein and utilize the dischargefrom the various embodiments of the trough that allows the liquid to bespread out across a diffuser plate to form an even film that isdischarged onto structured packing disposed beneath to enhance thevapor-liquid interaction therebetween. In accordance with the principlesof the present invention, the various embodiments herein facilitate thevapor being deflected from and not entering the channel between thetrough and the deflector baffle so as to cause entrainment. The variousvapor flow arrows shown in FIGS. 3-17 illustrate the advantages of thepresent invention in preventing liquid entrainment which reduces themass transfer efficiency in a chemical process column.

Various embodiments of the present invention are thus designed toprevent blasts of vapor from hitting the various orifices that areejecting liquid from the troughs so as to cause liquid entrainment. Byvectoring the vapor away from the trough in the manner shown, protectionis afforded. This has multiple advantages, including causing lessturbulence and less pressure drop. Various angles are shown herein, butmany different angles are contemplated within spirit and scope of thepresent invention. Angles can also vary in either direction. Noparticular angle is suggested herein as limiting the scope of thepresent invention and the various angles shown are to indicate aconfiguration that is designed to facilitate smooth vapor flow so as toreduce any pressure drop and reduce any entrainment. Likewise, thevarious embodiments of apertures in the bottom and side walls of thetroughs are not to be considered as limiting in that otherconfigurations are also contemplated. One specific reason that anorifice would be positioned on the bottom of a trough is so that anydebris or solids within the trough and carried by the liquid would noteasily plug the orifice. By having the position as shown herein, solidsplugging an orifice would be “flushed out.”

Further to the discussion of the operation of the present invention setforth above, it may be seen that various angles, as well as tapers, ofthe trough are shown. The tapers, may, in some configurations be anadvantage over a flat plate and/or the use of tubes. Likewise, tubes orconduit for the liquid discharge of the orifice may, in certainembodiments and operations, be more advantageous than not having suchtubes. It is fully contemplated within the spirit and scope of thepresent invention that either tubes for deflector plates and/orcontiguous deflector baffle and diffuser plate varieties have as setforth and shown herein may be utilized in accordance with principles ofthe present invention.

It may be seen that the various embodiments of the present invention arefurther designed to prevent the entrainment of liquid in the chemicalprocess tower during certain operations. For example, it should be notedthat at higher velocities, the closed configurations of FIG. 17 and thelike would probably be the best way to ensure that the least amount ofentrainment is manifested from liquid discharge. Similar considerationsoccur when flow configurations start to flood the underlying structuredpacking.

Referring now to the drawings of FIGS. 18A-18F, it may be seen that aone-piece drip tube having a closed-sided construction may beadvantageous. By closed-sided construction, the applicants herein referto a closure of side and back walls of the drip tube in the constructionthereof. Referring now to FIG. 18A, a one-piece, closed-sided drip tube1802 is shown in a straight configuration attached to a trough 1804 viahooks 1806 and 1808. In various embodiments, because of the close-sidedconstruction of the drip tube 1802, ascending vapor from beneath thetrough, as described above, is not given direct access for flow into thedrip tube 1802. Rather, ascending vapor flows in the directions ofarrows 1810 and 1812 around the drip tube 1802. In this manner, liquidentrainment resulting from, for example, high velocity vapor flow may begreatly reduced.

Referring now to FIGS. 18B-18F, it may be seen in the drawings that bothtriangular as well as rectangular configurations of drip tubes areshown. For example, in FIGS. 18B-18D and 18F, triangular configurations1814, 1818, 1830, and 1826 are shown. By way of further example, in FIG.18E, rectangular configuration 1832 is shown. Other shapes such asarcuate, oval, and circular may also be utilized in accordance with theprincipals of the present invention. The drip tubes are shown to beclosed by way of closures 1816, 1820, 1822, 1824, and 1828. In someembodiments, the closures may be spring-lock closures as shown withclosure 1822 in FIG. 18D.

In addition to the configurations shown in FIGS. 18A-18F, it may be seenthat, in various embodiments, the one-piece, closed-sided drip tubes asshown herein may be configured to be bent, angulated, or S-shapedrelative to a trough to discharge generally in a discharge regionbeneath the trough. It may also be seen that the one-piece, closed-sideddrip tubes as shown herein may be attached to the trough by variousattachment approaches. A combination of hooks may be utilized and/orsingle-point welding in various embodiments. Likewise, snap-on andbolt-on configurations may be incorporated for attachment of aclosed-sided drip tube in accordance with the principles of the presentinvention. Finally, the various embodiments of the present inventionillustrate methods of, and apparatus for reducing the disturbance ofliquid discharge from the various distributor troughs. As set forthabove, reductions in pressure drop and entrainment further facilitatesand enhances capacity and efficiency in a vapor-liquid contact column.

FIG. 19A is a diagrammatical side-elevational, cross-sectional view of aliquid distributor utilizing a plurality of break bars. A liquiddistributor 1900 includes a baffle plate 1902 positioned alongside atrough 1901. The trough 1901 is shown by way of example in FIG. 19 asincluding sidewalls 1910 and an angulated bottom region 1912, whichforms a generally V-shaped configuration. In other embodiments, thetrough 1901 may be constructed with any cross-sectional shape such as,for example, the shapes depicted above in any of FIGS. 3-17. Further,the liquid distributor 1900 may, in some embodiments, be constructedwith a second baffle plate (not shown) positioned on a side of thetrough 1901 opposite the baffle plate 1902.

The baffle plate 1902 includes a diffuser side 1922 facing the trough1901 and a deflector side 1924 opposite the diffuser side 1922 facingaway from the trough 1901. A liquid spreading region 1905 is disposed onthe diffuser side 1922. As shown in FIG. 19A, the liquid spreadingregion 1905 includes break bars 1904, 1906, 1908 that extend from thediffuser side 1922 of the baffle plate 1902. In FIG. 19A, the break bar1904 is shown as being disposed on a lower vertical portion 1914 of thebaffle plate 1902 with the break bars 1906 and 1908 being disposed on anangulated portion 1916 of the baffle plate 1902; however, in otherembodiments, the break bars 1904, 1906, 1908 may be disposed on thediffuser side 1922 of the baffle plate 1902 at any location. In atypical embodiment, the break bars 1904, 1906, 1908 are stamped orembossed into the baffle plate 1902; however, as shown in FIG. 19B, thebreak bars 1904, 1906, 1908 may be joined to the baffle plate 1902through a process such as, for example, welding, bolting, riveting,brazing, soldering, or other similar process.

As shown in FIG. 19C, in a typical embodiment, the break bars 1904,1906, 1908 extend across the diffuser side 1922 of the baffle plate 1902in a direction generally parallel to each other and generally parallelto a length of the baffle plate 1902. As shown in FIG. 19D, in someembodiments, the break bars 1904, 1906, 1908 may be angled with respectto an axis generally parallel to the length of the baffle plate 1902. Byway of example, the break bars 1904, 1906, 1908 are shown in FIG. 19D ashaving a chevron-like profile; however, in other embodiments, the breakbars 1904, 1906, 1908 may have any profile shape such as, for example,saw-tooth and the like. As shown in FIG. 19E, in some embodiments, thebreak bars 1904, 1906, 1908 may be curved. As shown in FIG. 19F, in someembodiments, the break bars 1904, 1906, 1908 may be segmented. While theliquid distributor 1900 includes the break bars 1904, 1906, 1908, liquiddistributors utilizing principles of the invention may include anynumber of break bars such as, for example, two or an integer numberbetween three and ten or more.

During operation, liquid escapes the trough 1901, via an upper aperture1918 and a lower aperture 1920, and contacts the diffuser side 1922 ofthe baffle plate 1902. During periods of operation where a flow rate ofthe liquid is very low, a surface tension of the liquid induces theliquid to flow approximately straight down the diffuser side 1922 of thebaffle plate 1902 in a direction generally perpendicular to the lengthof the baffle plate 1902. In such conditions, the liquid does notdistribute along a length of the diffuser side 1922 of the baffle plate1902. The liquid contacts the break bars 1904, 1906, 1908 and collectsbehind the break bars 1904, 1906, 1908. Surface tension induces theliquid to distribute along the length of the baffle plate 1902 andspread into a continuous film. When enough liquid has accumulated behindthe break bars 1904, 1906, 1908, the liquid spills over a top of thebreak bars 1904, 1906, 1908 and descends down the diffuser side 1922 ofthe baffle plate 1902 in a continuous film. Thus, the break bars 1904,1906, 1908 improve distribution of the liquid along the length of thediffuser side 1922 of the baffle plate 1902.

FIG. 19G is a diagrammatical side-elevational, cross-sectional view of aliquid distributor utilizing a plurality of ripples. A liquid spreadingregion 1905′ includes a plurality of ripples 1907 disposed on thediffuser side 1922 of the baffle plate 1902. In a typical embodiment,the plurality of ripples 1907 induce liquid to distribute along thelength of baffle plate 1902 and spread into a continuous film. Duringoperation, liquid escapes the trough 1901, via an upper aperture 1918and a lower aperture 1920, and contacts the liquid spreading region 1905on the diffuser side 1922 of the baffle plate 1902. The plurality ofripples 1907 distributes the liquid along the length of the baffle plate1902 and spreads the liquid into a continuous film. Thus, the pluralityof ripples 1907 improves distribution of the liquid along the length ofthe diffuser side 1922 of the baffle plate 1902. By way of example,FIGS. 19A, 19B, and 19G illustrate a single baffle plate. In otherembodiments, methods and systems utilizing the present invention couldinclude more than one baffle plate.

FIG. 20 is a diagrammatical side-elevational, cross-sectional view of aliquid distributor according to an exemplary embodiment. A distributortrough 2002 includes sidewalls 2004 and an angulated bottom region 2006which forms a generally V-shaped configuration. This shape of troughreduces pressure drop. Likewise, a deflector baffle 2008 is disposedgenerally parallel to the sidewalls 2004 of the distributor trough 2002.By way of example, FIG. 20 illustrates at least one deflector baffle2008; however, in other embodiments, liquid distributors utilizingprinciples of the invention may include deflector baffles disposed onboth sides of the distributor trough 2002. In a typical embodiment, thedeflector baffle is positioned to discharge liquid against at least onediffuser plate 2010 depending from the angulated bottom region 2006 ofthe distributor trough 2002.

Still referring to FIG. 20A, a liquid spreading region 2012 is disposedon the deflector baffle 2008. The liquid spreading region 2012 includesbreak bars 2104, 2016, and 2018 that extend from the deflector baffle2008. In FIG. 20A, the break bar 2018 is shown as being disposed the atleast one diffuser plate 2010 with the break bars 2014 and 2016 beingdisposed on an angulated portion 2020 of the deflector baffle 2008;however, in other embodiments, the break bars 2014, 2016, 2018, 2019 maybe disposed at any location. In a typical embodiment, the break bars2016, 2016, 2018, 2019 are stamped or embossed into at least one of thedeflector baffle 2008 and the at least one diffuser plate 2010; however,in other embodiments, the break bars 2014, 2016, 2018, 2019 may bejoined to the deflector baffle 2008 and the at least one diffuser plate2010 through a process such as, for example, welding, bolting, riveting,brazing, soldering, or other similar process. As shown in FIG. 20B, adistributor trough 2022 having a substantially flat bottom 2024 may alsobe utilized. In such embodiments, a perpendicular deflector baffle 2026is positioned alongside the distributor trough 2022. Break bars 2028,2030, 2032, 2033 are positioned on the perpendicular deflector baffle2026 and at least one diffuser plate 2034. As shown in FIG. 20C, aliquid spreading region 2012′ includes a plurality of ripples 2026disposed on at least one of the deflector baffle 2008′ and the at leastone diffuser plate 2010′. In a typical embodiment, the plurality ofripples 2026 induce liquid to distribute along the length of baffleplate 1902 and spread into a continuous film.

During operation, liquid escapes the distributor trough 2002 via atleast one of an upper aperture 2022 and a lower aperture 2024, andcontacts the deflector baffle 2008. During periods of operation where aflow rate of the liquid is very low, a surface tension of the liquidinduces the liquid to flow approximately straight down the deflectorbaffle 2008. In such conditions, the liquid does not distribute along alength of the deflector baffle 2008. The liquid contacts the break bars2014, 2016, 2018, 2019 and collects behind the break bars 2014, 2016,2018, 2019. Surface tension induces the liquid to distribute along thelength of the deflector baffle 2008 and spread into a continuous film.When enough liquid has accumulated behind the break bars 2014, 2016,2018, 2019, the liquid spills over a top of the break bars 2014, 2016,2018, 2019 and descends down the deflector baffle 2008 in a continuousfilm. Thus, the break bars 2014, 2016, 2018, 2019 improve distributionof the liquid along the length of the deflector baffle 2008.

FIGS. 21A-21B are diagrammatical side-elevational, cross-sectional viewsof a liquid distributor according to an exemplary embodiment. Referringto FIGS. 21A and 21B, a tube 2102 is positioned adjacent to a side wall2104 of a distributor trough 2106 to facilitate control of the liquiddischarge from the distributor trough 2106. As shown in FIG. 21A acontinuous deflector baffle 2112 is disposed alongside the distributortrough 2106. Break bars 2120, 2122, 2124 are shown disposed on thecontinuous deflector baffle 2112. As shown in FIG. 21B, a diffuser plate2108 is connected to, and extends from, a bottom region 2110 of thedistributor trough 2106. A deflector baffle 2109 is disposed alongsidethe distributor trough 2106. Break bars 2114, 2116, 2118, 2120 are showndisposed on the diffuser plate 2108 and the deflector baffle 2109. Byway of example, FIGS. 20A-21B illustrate a single baffle plate and asingle diffuser plate. In other embodiments, methods and systemsutilizing the present invention could include more than one baffle plateor more than one diffuser plate.

It is thus believed that the operation and construction of the presentinvention will be apparent from the foregoing description. While themethod and apparatus shown or described has been characterized as beingpreferred it will be obvious that various changes and modifications maybe made therein without departing from the spirit and scope of theinvention as defined in the following claims.

What is claimed is:
 1. A packed exchange tower, the packed exchangetower being of a type wherein vapor is injected therein for ascensiontherethrough and liquid is dispersed therethrough for downward flow, thepacked exchange tower comprising: one or more packing sections disposedin the tower; one or more liquid flow distributors positioned above theone or more packing sections, the one or more liquid flow distributorscomprising: a plurality of troughs for dispersing the liquidthereacross, at least one trough having disposed along a first side atleast one deflecting member, the at least one deflecting member having adeflector side facing outwardly of the at least one trough and adiffuser side facing the at least one trough, the at least onedeflecting member being angulated to generally follow a shape of the atleast one trough; at least one break bar disposed on the diffuser sideof the at least one deflecting member, the at least one break barinducing the liquid to flow along the diffuser side of the at least onedeflecting member in a continuous sheet; and a diffuser plate disposedgenerally perpendicularly to a bottom region of the at least one trough,wherein the at least one deflecting member extends along a length of thefirst side of the at least one trough and is constructed in a generallyreverse L-shaped configuration such that a lower region thereof isgenerally perpendicular to and spaced from the diffuser plate.
 2. Thepacked exchange tower of claim 1, wherein the diffuser plate ispositioned generally beneath a side of the at least one trough.
 3. Thepacked exchange tower of claim 1, wherein the diffuser plate ispositioned generally centrally beneath the at least one trough relativeto a horizontal plane.
 4. The packed exchange tower of claim 1, whereinthe at least one break bar is continuous.
 5. The packed exchange towerof claim 1, wherein the at least one break bar is curved.
 6. The packedexchange tower of claim 1, wherein the at least one break bar issegmented.
 7. The packed exchange tower of claim 1, wherein the at leastone break is oriented generally parallel to an adjacent break bar. 8.The packed exchange tower of claim 1, wherein the at least onedeflecting member is a continuous deflector baffle.
 9. A packed exchangetower, the packed exchange tower being of a type wherein vapor isinjected therein for ascension therethrough and liquid is dispersedtherethrough for downward flow, the packed exchange tower comprising:one or more packing sections disposed in the tower; one or more liquidflow distributors positioned above the one or more packing sections, theone or more liquid flow distributors comprising: a plurality of troughs,at least one trough in the plurality of troughs comprising: acurvilinear formation on a first side of a bottom region thereof; and anangulated formation on a second side of the bottom region thereof, thesecond side being opposite the at least one trough to the first side; adeflecting member along a selected side of the at least one trough, thedeflecting member having a deflector side facing outwardly of the atleast one trough and a diffuser side facing the at least one trough, thedeflecting member being angulated to generally follow a shape of the atleast one trough; the deflector side of the deflecting member beingpositioned for deflecting ascending vapor away from downward flow of theliquid on the diffuser side; at least one break bar disposed on thediffuser side of the deflecting member, the at least one break barinducing the liquid to flow along the diffuser side of the deflectingmember in a continuous sheet; and a diffuser plate disposed generallyperpendicularly to a bottom region of the at least one trough, whereinthe deflecting member extends along a length of the selected side of theat least one trough and is constructed in a generally reverse L-shapedconfiguration such that a lower region thereof is generallyperpendicular to and spaced from the diffuser plate.
 10. The packedexchange tower of claim 9, wherein the at least one break bar iscontinuous.
 11. The packed exchange tower of claim 9, wherein the atleast one break bar is curved.
 12. The packed exchange tower of claim 9,wherein the at least one break bar is segmented.
 13. The packed exchangetower of claim 9, wherein the at least one break bar is orientedgenerally parallel to an adjacent break bar.
 14. The packed exchangetower of claim 9, wherein the deflecting member is a continuousdeflector baffle.